Diagnostic Aids

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

If the Onstar® Call Center has not received any GPS data, this is an indication that the Onstar® call was a fail to voice and may be due to a failure in the National Cellular Network infrastructure. If this occurs, contact the General Motors Technical Assistance Center.
Inaccurate or age GPS position concerns made by a customer which are no longer present may have been due to the temporary loss of GPS signal reception by the vehicle. Conditions such as driving through tunnels or parking structures while making an Onstar® keypress will restrict the navigation antenna from a clear view of the satellites in the sky and may have caused this temporary data loss.

Fig 1: Global Positioning System (GPS) Data Not Current Or Inaccurate

Courtesy of GENERAL MOTORS CORP.